I am running Windows 10 Pro.
I am pretty sure it is the #6. When I saw the machine this morning it was the only one with the fan still spinning (all the others were stopped) and the machine was completely locked up....
Try to check your Win 10 version, Open Run type Winver and hit enter. I suggest using Win 10 latest update 1709.
If you sure that the GPU 6 is causing your problem, try to disable it when mining, you can disable it using device manager or hit number of your GPU on Claymore if you are using Claymore.
Yes, you need to increase your Virtual Memory, at least 16 Gb.
2000 Watt PSU is enough for your 8 Cards, but maybe something wrong with powering scheme.
System info says my Windows 10 build is 16922 version 1709. I only have 7 GPU's and have 56 gigs of virtual memory available. Just drove the 20 minutes to reboot the miner again since it crashed. I came into the room to find myself staring at the motherboard BIOS screen. There was a big WTF. Exited out of it and it rebooted back into the bios. Cut the power and it restarted into Windows 10.